Brake mechanism, joint actuator, and robot

ABSTRACT

The present disclosure relates to a brake mechanism, a joint actuator and a robot. The brake mechanism includes a friction member configured to be fixed to a rotor of the motor, a brake member abutting against one side of the friction member, a pushing member abutting against the other side of the friction member and configured to provide an adjustable pushing force to the brake member, a locking mechanism configured to prevent the brake member from rotating according to a brake command.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/661,178, filed Oct. 23, 2019, which is a continuation-in-part of PCTapplication No. PCT/CN2019/107470, filed Sep. 24, 2019. The disclosuresof the above-identified applications are hereby incorporated herein intheir entireties by reference.

TECHNICAL FIELD

The present disclosure relates to the field of brake technology, and inparticular to a brake mechanism, a joint actuator, and a robot.

BACKGROUND

A robot is a machine device that can perform a certain action taskautomatically. An actuator in each joint of the robot can drive a robotarm connected thereto to move. The actuator is provided with a brakemechanism for stopping movement of the robot arm or maintaining acertain spatial posture of the robot arm. If friction force of the brakemechanism in the robot is too large, it may cause impact to the brakemechanism and other components in the joint actuator during the brakeoperation, and damage may be caused. If the friction force is too small,the brake distance will be increased, which affects safety of robotcontrol.

SUMMARY

According to embodiments of the present disclosure, a brake mechanism, ajoint actuator, and a robot are provided to solve the above technicalproblems in the prior art.

In a first aspect, embodiments of the present disclosure provide a brakemechanism for a motor including: a friction member configured to befixed to a rotor of the motor; a brake member abutting against one sideof the friction member; a pushing member abutting against the other sideof the friction member and configured to provide an adjustable pushingforce to the brake member; and a locking mechanism configured to preventthe brake member from rotating according to a brake command.

In a second aspect, the embodiments of the present disclosure provide ajoint actuator including a motor and a brake mechanism described above,the friction member is fixedly connected to a rotor of the motor.

In a third aspect, embodiments of the present disclosure provide a robotincluding a joint actuator described above.

One or more embodiments are further described below with reference tothe drawings and specific embodiments. Other features, objects andbeneficial effects of the present disclosure will be apparent to thoseskilled in the art from the description of the specification, drawingsand claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a brake mechanism in accordance with anembodiment of the present disclosure.

FIG. 2 is an exploded view of the brake mechanism of FIG. 1 .

FIG. 3 is a right view of a friction member of the brake mechanism ofFIG.

FIG. 4 is a schematic view of a joint actuator in accordance withanother embodiment of the present disclosure.

FIG. 5 is a front view of the joint actuator of FIG. 4 where the motoris removed.

FIG. 6 is a perspective view of the joint actuator of FIG. 5 .

FIG. 7 is a schematic view of a stopping needle of a joint actuator inaccordance with another embodiment of the present disclosure.

FIG. 8 is a front view of a robot of the embodiment.

The additional details or examples used to describe the drawings aremerely one embodiment and should not be construed as limiting the scopeof any of the disclosed disclosure, the presently described embodiments,and the best mode of the disclosure as understood.

DESCRIPTION OF DRAWINGS REFERENCE

10, brake mechanism, 11, friction member, 111, groove, 12, brake member,13, pushing member, 14, locking mechanism, 141, stopping needle, 142,driving member, 15, fixing member, 151, screw thread, 152, fixing plate,1521, auxiliary groove, 153, limiting groove, 16, pushing nut, 17,washer, 171, limiting protrusion, 20, joint actuator, 21, motor cover,211, through hole, 22, motor, 221, rotor, 222, stator, 223, output end,30, robot, 31, robot arm, 32, joint.

DETAILED DESCRIPTION OF THE EMBODIMENTS

To enable the above objects, features and advantages of the presentdisclosure to be more clearly understood, specific embodiments of thepresent disclosure will be described in detail below with reference tothe accompanying drawings. Numerous specific details are set forth inthe following description in order to facilitate a thoroughunderstanding of the present disclosure. However, the present disclosurecan be practiced in many other ways different from those describedherein, and similar modifications can be made by those skilled in theart without departing from the meaning of the present disclosure, suchthat the present disclosure is not limited by the specific embodimentsdisclosed below.

It should be noted that when an element is referred to as being “fixed”to another element, it can be directly on the other element or it canalso be presence of a central element. When an element is considered tobe “connected” to another element, the element can be directly connectedto the other element or it can be simultaneous presence of the centralelement. The terms “vertical”, “horizontal”, “left”, “right” and thelike used herein are for illustrative purposes only and are not meant tobe the only embodiment.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as generally understood by those skilled in theart of the present disclosure. The terms used herein in thespecification of the disclosure are for the purpose of describingspecific embodiments only and are not intended to limit the disclosure.The various technical features of the above-described embodiments can bearbitrarily combined, and for the sake of brevity, all possiblecombinations of the various technical features in the above-describedembodiments are not described. However, as long as there is nocontradiction in the combination of these technical features, it shouldbe deemed to be within the scope of this specification.

As shown in FIGS. 1 and 2 , a brake mechanism 10 for a motor is providedin one embodiment. The brake mechanism 10 may include a friction member11, a brake member 12, a pushing member 13, and a locking mechanism 14.The friction member 11 is configured to be fixed to a rotor 221 of amotor 22. The friction member 11 abuts against one side of the brakemember 12. The pushing member 13 abuts against the other side of thebrake member 12 to provide an adjustable pushing force to the brakemember 12. The locking mechanism 14 is used to prevent the brake member12 from rotating according to a brake command.

By adjusting the pushing force of the pushing member 13 to the brakemember 12, friction force between the friction member 11 and the brakemember 12 can be adjusted, such that the friction force between thefriction member 11 and the brake member 12 can be maintained within anappropriate range. Specifically, the rotor 221 of the motor 22 drivesthe friction member 11 fixed to the rotor 221 to rotate during itsrotation, and the brake member 12 rotates simultaneously under thefriction force. When the rotor 221 of the motor 22 stops rotating andrequires to be held in a specific position, the locking mechanism 14cooperates with the brake member 12 to prevent the brake member 12 fromrotating. The friction member 11 and the rotor 221 of the motor 22 alsogradually stop under the friction force. After a period of usage, thefriction member 11 and/or the brake member 12 will be worn, resulting ina change of the friction force between the friction member 11 and thebrake member 12. In this situation, the friction force between thefriction member 11 and the brake member 12 can be restored to anappropriate range by adjusting the pushing force of the pushing member13 against the brake member 12.

Specifically, when the pushing member 13 is an elastic member, thepushing force of the pushing member 13 to the brake member 12 can beadjusted by changing compression amount of the pushing member 13.Regarding the compression amount of the pushing member 13, a limitingmember can be provided on a side of the pushing member 13 away from thebrake member 12, and the distance between a limiting member and thebrake member 12 can be adjusted, such that the compression amount of thepushing member 13 abutted between the brake member 12 and the limitingmember can be changed.

Specifically, the pushing member 13 can be an annular pushing spring, acolumnar compression spring, a set of electromagnets that can generatemutually exclusive force, or other devices that can generate the pushingforce, which are not specifically limited hereto.

Further, when the pushing member 13 is the elastic member, the pushingmember 13 is in a compression state in operation. Thus, even if thefriction member 11 and the brake member 12 are somehow worn during use,the deformation of the pushing member 13 can enable the friction member11 and the brake member 12 to be in an abutting state constantly, whichmay make sure that the friction force between the brake member 12 andthe friction member 11 can be maintained within the appropriate range.In addition, it is not necessary to pre-tighten an excessive forcebetween the brake member 12 and the friction member 11 at an initialstage of assembling for a certain friction force between the frictionmember 11 and the brake member 12 during installation and commissioning.It is only necessary to compress the pushing member 13 to a certainamount during assembling, such that the friction force between the brakemember 12 and the friction member 11 can be maintained within theappropriate range, and the wear of the friction member 11 and the brakemember 12 may be reduced. During use, although the pushing member 13 iselongated as the brake member 12 and the friction member 11 are worn,the friction force between the brake member 12 and the friction member11 can be still maintained within the appropriate range.

Apparently, if the pushing member 13 is a set of electromagnets, theycan act the same as the elastic member. Even if there is the wearbetween the friction member 11 and the brake member 12, the brake member12 and the friction member 11 can always be abutted due to the exclusiveforce between the electromagnets, such that the friction force can bemaintained within the appropriate range. In other words, the frictionforce between the brake member 12 and the friction member 11 can bedynamically adjusted through the pushing member 13.

Specifically, in one embodiment, as shown in FIGS. 1, 2, 5, and 6 , whenthe pushing member 13 is the elastic member, it can be an annularpushing spring. One side of the pushing spring abuts against the brakemember 12 to provide the pushing force to the brake member 12.

As shown in FIGS. 1, 2, 5, and 6 , upper and lower surfaces of theannular pushing spring axially undulate to form a wave-shaped annularstructure so as to abut against the brake member 12. Each contact pointof the pushing spring protruding with respect to the brake member 12provides the pushing force to the brake member 12.

The contact points are uniformly distributed on the pushing spring in acircumferential direction, such that the brake member 12 is moreuniformly stressed.

Alternatively, in one embodiment, the pushing member 13 may include anumber of columnar compression springs spaced apart in thecircumferential direction of the brake member 12. One end of thecompression spring abuts against the brake member 12 to provide thepushing force to the brake member 12.

In other words, by circumferentially distributing the compressionsprings to provide the pushing force to the brake member 12, the brakemember 12 is tightly pressed on the friction member 11 to secure thefriction force between the brake member 12 and the friction member 11.

Further in one embodiment, when the pushing member 13 is a set ofelectromagnets, the pushing member 13 can include a first electromagnetand a second electromagnet. The first electromagnet abuts against thebrake member 12, and the second electromagnet is arranged correspondingto the first electromagnet. When both of the first electromagnet and thesecond electromagnet are energized, the mutually exclusive force isgenerated between the first electromagnet and the second electromagnet.The magnetic force of the first electromagnet and/or the secondelectromagnet is adjustable.

During use, the pushing force of the pushing member 13 to the brakemember 12 can be adjusted by adjusting the magnetic force of the firstelectromagnet and/or the second electromagnet, such that the frictionforce between the brake member 12 and the friction member 11 can beadjusted. Furthermore, by using the first electromagnet and the secondelectromagnet, the process of adjusting the pushing force can beautomatically controlled.

Further, in one embodiment, as shown in FIGS. 1, 2, 5, and 6 , in orderto improve the uniformity of the force applied by the pushing member 13to the brake member 12, a washer 17 can be further provided between thepushing member 13 and the brake member 12. The washer 17 is clampedbetween the brake member 12 and the pushing member 13. Moreover, thewasher 17 is configured to avoid direct contact between the pushingmember 13 and the brake member 12, thus avoiding the occurrence offriction between the pushing member 13 and the brake member 12 when thebrake member 12 rotates.

Further, in one embodiment, as shown in FIGS. 1, 2, 5, and 6 , the brakemechanism 10 may further include a fixing member 15. Both of thefriction member 11 and the brake member 12 are sleeved on the fixingmember 15. The friction member 11 is circumferentially fixed withrespect to the fixing member 15, and the brake member 12 iscircumferentially slidable with respect to the fixing member 15.

During general use, the fixing member 15 is connected to the rotor 221of the motor 22 or the like. During normal operation, the rotor 221 ofthe motor 22 drives the fixing member 15 together with the frictionmember 11 and the brake member 12 to rotate.

During braking, the locking mechanism 14 prevents the brake member 12from rotating, and the brake member 12 prevents the friction member 11from rotating under the friction force between the brake member 12 andthe friction member 11, thereby preventing the rotor 221 of the motor 22from rotating.

When the rotation speed of the rotor 221 of the motor 22 is relativelylow, static friction force between the brake member 12 and the frictionmember 11 is large enough to prevent the friction member 11 fromrotating with respect to the brake member 12. The friction member 11 iscircumferentially fixed to the fixing member 15, thereby achievingbraking. When the rotation speed of the rotor 221 of the motor 22 isrelatively high, although the brake member 12 is prevented fromrotating, the friction member 11 and the fixing member 15 continue torotate due to large kinetic energy of the rotor 221 of the motor 22. Arelative rotation occurs between the friction member 11 and the brakemember 12. The friction member 11, the fixing member 15, and the rotor221 of the motor are gradually stopped under a dynamic friction forcebetween the friction member 11 and the brake member 12.

Specifically, as shown in FIG. 2 , the fixing member 15 can be of acylinder shape, for example, a fixing cylinder. Alternatively, thefixing member 15 can be columnar in shape, such as a cylindrical fixingmember, a prismatic fixing member, or the like.

Further, as shown in FIG. 2 , in one embodiment, both of the frictionmember 11 and the brake member 12 are annular in shape, and both of thefriction member 11 and the brake member 12 are sleeved on the fixingmember 15.

Further, as shown in FIGS. 1, 2, 5, and 6 , when the washer 17 isprovided between the brake member 12 and the pushing member 13, thewasher 17 can also be sleeved on the fixing member 15. The washer 17 isclamped between the brake member 12 and the pushing member 13, and thewasher 17 is circumferentially fixed with respect to the fixing member15.

In other words, when the brake member 12 is circumferentially rotatedwith respect to the fixing member 15, relative rotation also takes placebetween the washer 17 and the brake member 12. The washer 17 isstationary in the circumferential direction with respect to the fixingmember 15, such that the pushing member 13 is stationary with respect tothe fixing member 15, which ensures a stability of the pushing member13.

Specifically, as shown in FIG. 2 , in one embodiment, when the washer 17is annular in shape, the manner in which the washer 17 and the fixingmember 15 are circumferentially fixed can be as that, a concavo-convexfitting structure is provided between an inner ring of the washer 17 andthe fixing member 15, so as to prevent the washer 17 from rotating inthe circumferential direction with respect to the fixing member 15.

Further specifically, as shown in FIG. 2 , an outer circumferentialsurface of the fixing member 15 is provided with a limiting groove 153that extends along an axial direction of the fixing member 15, and theinner ring of the washer 17 is provided with a limiting protrusion 171corresponding to the positioning groove 153.

When the washer 17 is sleeved on the fixing member 15, the limitingprotrusion 171 of the inner ring of the washer 17 is located in thelimiting groove 153, thereby restraining the circumferential movement ofthe washer 17 with respect to the fixing member 15.

Further specifically, in one embodiment, the washer 17 is apolyoxymethylene (POM) washer. The washer 17 can also be made of otherengineering plastics having an appropriate coefficient of friction, andis not particularly limited hereto.

Further, in one embodiment, as shown in FIGS. 1, 2, 5, and 6 , the brakemechanism 10 may further include a pushing nut 16 that is sleeved on thefixing member 15. The pushing nut 16 abuts against a side of the pushingmember 13 away from the brake member 12. The fixing member 15 isprovided with a screw thread 151 at a position corresponding to thepushing nut 16, and the screw thread 151 corresponds to the pushing nut16.

When the pushing member 13 is an elastic member, by adjusting the depthat which the pushing nut 16 is screwed into the fixing member 15, i.e.,by adjusting the distance between the pushing nut 16 and the brakemember 12, the amount of pre-compression of the elastic member can beadjusted, such that the friction force between the brake member 12 andthe friction member 11 can be always maintained within the appropriaterange.

Further, in one embodiment, as shown in FIG. 2 , one end of the fixingmember 15 adjacent to the friction member 11 may be provided with afixing plate 152 that is connected to the fixing member 15. An outerdiameter of the fixing plate 152 is greater than an outer diameter ofthe fixing member 15, and the friction member 11 is fixedly connected tothe fixing plate 152, thereby indirectly achieving a fixed connectionbetween the friction member 11 and the fixing member 15 in thecircumferential direction.

Specifically, the friction member 11 can be adhered to the fixing plate152. For example, as shown in FIG. 2 , the fixing plate 152 may beprovided with an auxiliary groove 1521 on a side surface thereofopposite to the friction member 11. The auxiliary groove 1521 is used toplace adhesive. Thus, a fixed connection between the fixing plate 152and the friction member 11 can be achieved by the adhesive.

Further, in one embodiment, the friction member 11 can be apolycarbonate (PC) friction sheet or other engineering plastic having anappropriate coefficient of friction, and is not particularly limitedhereto.

The brake member 12 can be made of a metal material, such as a metalbrake member, or other material having a certain strength.

Further, in one embodiment, as shown in FIG. 3 , the friction member 11may be provided with a number of grooves 111 on a side surface thereofopposite to the brake member 12. The grooves 111 extend radially on thefriction member, and the grooves 111 are spaced apart in thecircumferential direction of the friction member 11.

When the friction between the friction member 11 and the brake member 12generates powder, the generated powder can be temporarily stored in thegroove 111, thus preventing the powder from affecting the friction forcebetween the friction member 11 and the brake member 12.

Further, as shown in FIG. 3 , the groove 111 extends to the outercircumferential surface of the friction member 11, such that the powdertemporarily stored in the groove 111 can be discharged from the groove111.

Further, in another embodiment, as shown in FIG. 4 , a joint actuator 20is provided, which includes a motor 22 and the aforementioned brakemechanism 10. The friction member 11 is fixed to a rotor 221 of themotor 22.

Specifically, when the fixing member 15 is included in the brakemechanism 10, the rotor 221 of the motor 22 is connected to the fixingmember 15. During normal operation, the rotor 221 of the motor 22rotates with respect to the stator 222, thus driving the output end 223to move simultaneously. When the output end 223 moves to the targetposition and needs to be stopped, the brake mechanism 10 prevents therotor 221 of the motor 22 from rotating under the friction force,thereby stopping the output end 223 from moving.

By providing the brake mechanism 10 described in any of the aboveembodiments in the joint actuator 20, the friction force between thefriction member 11 and the brake member 12 can be always maintainedwithin the appropriate range during use. The impact on other componentsof the joint actuator 20 during brake may be reduced, and the purpose ofbrake can also be achieved.

Further, in one embodiment, as shown in FIGS. 4 to 6 , the lockingmechanism 14 may include a stopping needle 141 and a driving member 142connected to each other. An outer ring of the brake member 12 isprovided with brake teeth, and the stopping needle 141 is disposed at aposition corresponding to the brake teeth. The driving member 142 isused to drive the stopping needle 141 to stretch out and retract.

When it is required to brake, the driving member 142 drives the stoppingneedle 141 to stretch out, and the stopping needle 141 contacts thebrake teeth to prevent the brake member 12 from rotating, thus achievingbraking. When it is not required to brake, the driving member 142 drivesthe stopping needle 141 to retract, such that the stopping needle 141 isoffset from the brake member 12, thereby enabling the fixing member 15which rotates together with the rotor 221 of the motor 22, and the eachcomponent sleeved on the fixing member 15 to rotate.

Further, as shown in FIGS. 5 and 6 , in one embodiment, one end of thestopping needle 141 adjacent to the brake member 12 is conical in shape,therefore it is effectively prevented that the stopping needle 141 isstuck with the brake member 12 when the stopping needle 141 is stretchedout.

Specifically, as shown in FIG. 7 , when an inclination angle of theconical surface of the stopping needle 141 is Q, and a frictioncoefficient μ=tanQ, then Q=arctan μ, the brake member is not easilystuck when being in contact with the stopping needle 141.

Further, as shown in FIGS. 4 to 6 , the joint actuator 20 may furtherinclude a motor cover 21. The driving member 142 is an electromagneticdriving member located on an outer side of the motor cover 21. The brakemechanism 10 is located on an inner side of the motor cover 21. Themotor cover 21 is provided with a through hole 211, the stopping needle141 extends through the through hole 211 and corresponds to the brakemember 12.

The fixing member 15, the friction member 11, and other componentsdriven by the rotor 221 of the motor 22 rotate with the rotor 221 of themotor 22 on the inner side of the motor cover 21, while theelectromagnetic driving member and the stopping needle 141 arestationary with respect to the motor cover 21. When it is required tobrake, the electromagnetic driving member 142 drives the stopping needle141 to stretch out, thus stopping the brake member 12 on the inner sideof the motor cover 21, thereby achieving braking.

Further, in another embodiment, as shown in FIG. 8 , a robot 30 isprovided. The robot 30 may include the joint actuator 20 described inany of the above embodiments.

Specifically, the joint actuator 20 can be located in a robot arm 31 ofthe robot 30 to control the brake process of the robot arm 31.

By providing the joint actuator 20 described in any of the aboveembodiments in the robot 30, the friction force between the frictionmember 11 and the brake member 12 can be maintained within theappropriate range. Impact during braking may be reduced and largebraking stroke due to poor friction which may affect the safety ofbreaking of the robot 30 may be avoided.

In addition, when the robot 30 is in a stationary state, the jointactuator 20 is in a brake state. When an external impact or an externalforce is applied to the robot arm 31 of the robot 30, if the externalforce exceeds a predetermined value, relative rotation will occurbetween the friction member 11 and the brake member 12, thereby avoidingthe damage to transmission components in the joint 32 of the robot 30 bythe external impact or the excessive force.

Specifically, in one embodiment, as shown in FIG. 8 , the robot 30further includes a number of robot arms 31 and a number of joints 32.The robot arms 31 are sequentially connected. Adjacent robot arms 31 areconnected via the joints 32. Each of the joints 32 is provided with thejoint actuator 20.

For example, the robot 30 can be a six axis robot or a seven axis robot.The robot 30 can correspondingly include six joints 32 or seven joints32, and the robot arms 31 connected to the joints 32.

During normal operations of the robot 30, the rotor 221 of the motor 22rotates with respect to the stator 222, the output end 223 transmits therotation to one of the adjacent robot arms 31, and drives the robot arm31 to rotate with respect to another adjacent robot arm 31, therebyperforming the corresponding action. When the robot arms 31 are moved tothe target position, it is required to prevent the motor 22 fromcontinuing to rotate by a brake process and make the robot arm 31 tostop at the target position. By employing the above-described jointactuator 20, the wear between the friction member 11 and the brakemember 12 can be reduced while the precision and accuracy of themovement of the robot 30 can be ensured.

The technical features of the above-described embodiments can bearbitrarily combined. For the sake of brevity of description, allpossible combinations of the respective technical features in theabove-described embodiments have not been described, however, as long asthere is no contradiction in the combination of these technicalfeatures, it should be deemed to be the scope of the specification.

The above-described embodiments represent only several embodiments ofthe present disclosure, the description of which is more specific anddetailed, but is not to be construed as limiting the scope of thedisclosure. It should be noted that, for those of ordinary skill in theart, several modifications and improvements can be made withoutdeparting from the concept of the present disclosure, which fall withinthe scope of the present disclosure. Therefore, the scope of protectionof the disclosure patent shall be subject to the appended claims.

What is claimed is:
 1. A brake mechanism for a motor, the brakemechanism comprising: a friction member configured to be fixed to arotor of the motor; a brake member, the friction member abutting againstone side of the brake member; a pushing member abutting against theother side of the brake member and configured to provide an adjustablepushing force to the brake member; a locking mechanism configured toprevent the brake member from rotating according to a brake command; anda fixing member; wherein the friction member and the brake member areannular in shape; wherein the friction member and the brake member aresleeved on the fixing member; wherein the friction member iscircumferentially fixed with respect to the fixing member; and whereinthe brake member is circumferentially slidable with respect to thefixing member; wherein the friction member is provided with a pluralityof grooves on a side surface thereof opposite to the brake member, theplurality of grooves extend radially on the friction member, and theplurality of the grooves are spaced apart in a circumferential directionof the friction member.
 2. The brake mechanism of claim 1, furthercomprising a pushing nut sleeved on the fixing member; wherein thepushing nut abuts against a side of the pushing member away from thebrake member; wherein the fixing member is provided with a screw threadat a position corresponding to the pushing nut, and the screw threadcorresponding to the pushing nut.
 3. The brake mechanism of claim 1,wherein one end of the fixing member adjacent to the friction member isprovided with a fixing plate connected to the fixing member; an outerdiameter of the fixing plate is greater than an outer diameter of thefixing member; and the friction member is fixedly connected to thefixing plate.
 4. The brake mechanism of claim 3, wherein the fixingplate is provided with an auxiliary groove on a side surface thereofopposite to the friction member; the auxiliary groove is configured toplace an adhesive; and the friction member is adhered to the fixingplate.
 5. The brake mechanism of claim 1, further comprising a washersleeved on the fixing member; wherein the washer is clamped between thebrake member and the pushing member, and the washer is circumferentiallyfixed with respect to the fixing member.
 6. The brake mechanism of claim5, wherein the washer is annular in shape; a concavo-convex fittingstructure is provided between an inner ring of the washer and the fixingmember, the concavo-convex fitting structure is configured to preventthe washer from rotating in the circumferential direction with respectto the fixing member.
 7. The brake mechanism of claim 6, wherein anouter circumferential surface of the fixing member is provided with alimiting groove extending along an axial direction thereof; the innerring of the washer is provided with a limiting protrusion correspondingto the limiting groove.
 8. The brake mechanism of claim 1, furthercomprising a washer clamped between the brake member and the pushingmember.
 9. The brake mechanism according to claim 5, wherein the washeris a polyoxymethylene (POM) washer.
 10. The brake mechanism of claim 1,wherein the pushing member is an annular pushing spring, one side of thepushing spring abuts against the brake member to provide a pushing forceto the brake member.
 11. The brake mechanism of claim 1, wherein thepushing member comprises a plurality of columnar compression springs,the plurality of compression springs are spaced apart in thecircumferential direction of the brake member, one end of thecompression spring abuts against the brake member to provide a pushingforce to the brake member.
 12. The brake mechanism of claim 1, whereinthe pushing member comprises a first electromagnet and a secondelectromagnet, the first electromagnet abuts against the brake member,the second electromagnet is arranged corresponding to the firstelectromagnet; mutually exclusive force is generated between the firstelectromagnet and the second electromagnet when the first electromagnetand the second electromagnet are energized; and magnetic force of thefirst electromagnet and/or the second electromagnet is adjustable.
 13. Ajoint actuator comprising a motor and a brake mechanism of claim 1, thefriction member being fixedly connected to a rotor of the motor.
 14. Thejoint actuator of claim 13, wherein the locking mechanism comprises astopping needle and a driving member connected to each other, an outerring of the brake member is provided with brake teeth, the drivingmember is configured to drive the stopping needle to stretch out andretract, the stopping needle is capable of stretching out to be incontact with the brake teeth in response to the brake command to preventthe brake member from rotating.
 15. The joint actuator of claim 14,wherein one end of the stopping needle adjacent to the brake member isconical in shape.
 16. The joint actuator of claim 14, further comprisinga motor cover; wherein the driving member is an electromagnetic drivingmember located on an outer side of the motor cover; the brake mechanismis located on an inner side of the motor cover; the motor cover isprovided with a through hole, the stopping needle extends through thethrough hole and corresponds to the brake member.
 17. A robot comprisingthe joint actuator of claim
 13. 18. The robot of claim 17, furthercomprising a plurality of robot arms and a plurality of joints; whereinthe plurality of robot arms are sequentially connected, adjacent robotarms are connected via the joints, each of the joints is provided withthe joint actuator.